Direct Intravascular Observation of Leiomyosarcoma in Inferior Vena Cava Using Nonobstructive Generalized Angioscopy

A 51-year-old man with abdominal pain was referred for further investigation. Contrast-enhanced computed tomography (CT) revealed a large tumor obstructing the inferior vena cava (IVC) within the intraperitoneal cavity (Figure A,B). Based on ¹⁸F-fluorodeoxyglucose positron emission tomography/CT, a malignant tumor was suspected (Figure C,D). However, because it was unclear whether the tumor was of IVC or intraperitoneal origin, and whether it was a thrombus or a tumor within the IVC, we performed direct intravascular observation using nonobstructive generalized angioscopy (NOGA; Fiber Tech, Chiba, Japan). Immediately after IVC venography through the right femoral vein (Figure E), NOGA was performed through a 6Fr sheath and showed a mesh appearance of the tumor within the IVC (Figure F1,2; Supplementary Movie 1) that differed from the normal vessel wall (Figure F3; Supplementary Movie 2). Hence, the tumor was of IVC origin and not a thrombus within the IVC. Subsequently, the patient underwent open abdominal surgery (Figure G) and was diagnosed with leiomyosarcoma after histopathological and immunostaining for α-smooth muscle actin (Figure H).

Figure.

(A,B) Contrast-enhanced computed tomography showing a large tumor obstructing the IVC within the intraperitoneal cavity. (C,D) ¹⁸F-fluorodeoxyglucose positron emission tomography/CT suggests a malignant tumor (arrows). (E) IVC venography through the right femoral vein. (F) Nonobstructive generalized angioscopy (NOGA) was performed through a 6Fr sheath (F1–3 correspond to arrows in E). (G) open abdominal surgery. CIA, common iliac artery; CIV, common iliac vein; IVC, inferior vena cava; Rt, right. (H) Histopathological (H1) and immunostaining (H2) results indicative of leiomyosarcoma. α-SMA, α-smooth muscle actin; H&E, hematoxylin-eosin.

Leiomyosarcomas are rare malignant tumors of smooth muscle origin, usually in the uterus and gastrointestinal tract, and venous primary origin is extremely rare. NOGA has been used to directly visualize the intracoronary structure and provide substantial information pertaining to macroscopic pathology in patients. Direct observation of a leiomyosarcoma by intravascular angioscopy as seen in this patient has been rarely reported in the literature, but NOGA could provide minimally invasive preoperative evaluation and visualization of intravascular tumor characteristics and invasion.

Supplementary Files

Supplementary Movie 1. Leiomyosarcoma.

Supplementary Movie 2. Normal vessel wall.

Please find supplementary file(s);

https://doi.org/10.1253/circj.CJ-23-0724